Memory Card Has RAW Format

"My memory card has changed to RAW file system which was FAT32 before. I have used this memory card for a few years in my mobile phone. Yesterday, I plugged my mobile phone to my computer through a USB cable and saved some music to the memory card. When I was transferring the music, Windows system says please insert a disk into drive. Then, I unplugged the mobile phone and reconnected it to my computer again, this time the Windows recognized my memory card as a RAW drive and it prevents me from accessing any data on the card. I also tried to move the memory card out of my mobile phone and connect it to my PC via a card reader, but system still detected it as a RAW drive. Can anybody tell me what is wrong with my memory card and how to convert RAW to FAT32 with data back?"

Memory Stick Says It Needs Formatting

"I have a memory stick which contains lots of data, but it says needs to be formatted when I tried to access data on it. Inserting the memory stick to my computer, Windows system recognizes it as a RAW disk and asks me to format it before I can use it. CHKDSK says it is not available for RAW drives on memory card. I have searched online, and many people that the memory stick is corrupted. I need to use a data recovery program to get back files on an unformatted memory stick. So I hope somebody can recommend a useful data recovery tool with which I can recover files off the unformatted memory stick and fix the notformatted error."